There is a bit of confusion over the different modes the computer can enter so im going to try and clear this up for everyone.
MAF Closed Loop-MAF is Active, Main fueling O2 sensors are ActiveMAF Open Loop-MAF is Active, Main fueling O2 sensors are Inactive or removed
- Most Stock LS2's run in this mode corrections are made by the MAF, VE table & O2 sensors at part throttle
Speed Density Closed Loop(CLSD or SDCL)-Maf is inactive, removed or Failed, Main fueling O2 sensors are Active
- Many use this mode when the o2 sensors cannot be trusted for whatever reason ie Big cam, LT's, etc.
Speed Density Open Loop(OLSD or SDOL)-Maf is inactive, removed or Failed, Main fueling O2 sensors are Inactive
- Many revert to this mode after doing VE tuning in SDOL mode so the computer can make some corrections for fueling
- LS2's & LS7's use both the high & low octane tables even when they revert to Speed Density
- E40 PCM'd LS2's have only 1 VE table
- E38/E67 PCM'd cars/trucks don't have a standare VE table at all
Bottom Line is to remember Is Speed Density mode doesnt dictate if your in Open Loop or Closed Loop.
- Most will say this is best for VE tuning because you have complete control over what the engine wants to do.
- Setup your OLFA tables as you'd like to drive around town
- Setup your PE tables as you'd like to drive around town
- Just remember the computer will always command whatever table is richest so keep an eye on any adder/multiplyer tables that may be in effect such as Cat Over Temp.